Storage battery paste with amino dye as ion exchange expander



Patented June 30, 1953 STORAGE BATTERY PASTE WITH AMINO DYE AS ION EXCHANGE EXPANDER Carl H. Rasch, North Tonawanda, N. Y. No Drawing. Original application February 27,

1946, Serial No. 650,759. Divided and this application July 6, 1950, Serial No. 177,345

2 Claims. I

The present invention relates to wet storage batteries of the lead-acid type and has'particular reference to the negative plates of such batteries and, more especially, to the pastes employed in making up such plates.

This is a continuation in part of Serial No. 483,189, filed April 15, 1943, which became abandoned subsequent to the filing of Serial No. 650,759 and is a division of the latter, which has now matured into Patent No. 2,514,415, dated July 11,1950.

It has been well known in the art, for some time, that storage batteries of the type contemplated tend to fail at low temperatures. Many diverse suggestions have been made relative to the incorporation of so-called expanders into negative lead battery plates with the object in View of increasing the initial capacity under conditions of high rate and lowtemperature discharge and of maintaining such capacity over a longer period of useful life than that of plates not made with the addition of expanders as capacity aids.

Thus, in the prior art, it has been suggested to employ, as expanders, such unrelated materials as carbonized hemp, natural humins and lignins, sawdust, and waste sulphite liquor. It is believed that when a battery is discharged, metallic lead combine with sulfate ions forming lead sulfate, thereby releasing electric energy which flows in the external battery circuit. The function of the particles of ion exchange material in the plate is to render sulfate ions quickly available for the metallic lead. It is not known just Why or how the exchange compound takes on sulfate ions, but there appears to be no dispute that some sort of loose bond exists between the exchange compound and sulfate ions and that during discharge, lead sulfate is formed.

Reversal of the process and regeneration of the exchange resin occurs when, under the infiuence of a charging current, the lead sulfate, PbSOi, is torn apart, the sulfate ions being set free and becoming available to at least in part recombine with ion exchange material. Although all of these materials appear to aid the capacity to some extent, non fulfills, completely, the desired roll in this connection.

It is an object of the present invention to provide a negative plate for a lead-acid storage battery which possesses an increased capacity at low temperature.

It is also an object of the invention to provide an improved composition or paste adapted to be used upon the negative plate of a leadthe manufacture of negative plates of lead-acid storage batteries which results in a battery of a relatively longer useful life, during operation at low temperature, than is the case with batteries heretofore provided.

In accordance with the present invention, the negative plate of a storage battery is prepared from a paste which contains, incorporated therein, a relatively high molecular weight organic compound in finelydivided condition insoluble in sulfuric acid and which'is' susceptible of ion exchange or which possesses an ionic affinity for anions, particularly the sulfate ion, SO4=.

The paste contains about 99% litharge; about 0.1 to 0.5% finely divided barium sulfate; about 0.1 to 0.5% of gas black or lamp black, and from 0.1 to 0.5% of the acid-insoluble high molecular weight expander of the present invention. The product is made into apaste by acidifying with sulfuric acid of the desired gravity, and sufficient water to make the paste workable. This paste is applied to a lead grid in the usual Way and a negative plate suitable for use in the usual lead accumulator thus manufactured.

A. paste which is purely illustrative of the invention, and not limitative thereof, was made from the following ingredients:

Litharge pounds 1980 Finely divided barium sulfate do 10 Lamp black do 4 Phenylenediamine-formaldehyde resin do 6 Sulfuric acid, 1.250 sp. gr gallons 21 Water, sufficient to produce paste do 16 3 in lead storage battery pastes. Like the resinous condensation products, these additional materials contain amine radicals or substituted amines. Thus, certain organic dyes resulting from the condensation of amines with other organic residues appear to function in the same manner as the amine condensation resins. For instance, Erie Black when incorporated to the extent of about 1% or within the range 0.5 to 2.0% increases the discharge rate at low temperature operation of lead-acid storage batteries. This dye may be considered as a condensation product ofbenzidine, phenylenediamine, aniline and amidonapthol disulfonic acid.

Dyes other than Erie Black but which like Erie Black contain the NH2 group, function in the same fashion. Cotton Yellow may be mentioned as an example of a dye of this type as well as Fast Acid Violet, the latter compound being an example of a substituted NH2 group. These dyes, like the resinous condensation products, are relatively high molecular weight compounds, are insoluble in 40% sulfuric acid and contain an amine group.

Although the exact mechanism attending the functioning of these materials in pastes for leadacid storage batteries is not definitely known, it is believed that all of the compounds mentioned herein and of the class of condensation products of an amine and an organic compound, are capable of reacting as ion exchange materials and are thus capable of fixing anions such as SO4=. That is to say, due to the capacity of the organic aminecompound to combine with anions, a relatively large amount of such anion is available on the negative plate for reaction with metallic lead during the period of discharge, thus avoiding the necessity of awaiting for slow diffusion procedures to provide such 804 However, whatever the true mechanism and function of these high molecular weight condensation products of an amine and an organic compound may be, they all function in the same fashion, namely, to permit of higher discharge capacities at low temperature.

Although specific examples have been given of certain high molecular weight condensation products of amine and aromatic organic compounds, the present invention is not restricted to the specific examples given, but the scope of the invention is defined by the claims appended hereto.

What is claimed is:

1. For a storage battery of the lead'acid type, a plate having a paste thereon comprising an active lead compound and 0.1% to 2%, based on the Weight of the paste, of an amino anion exchange body in small discrete particles insoluble in dilute sulfuric acid as an expander, said body comprising an amino organic dye containing an amino group and insoluble in dilute sulfuric acid whereby said compound on discharge of the battery facilitates the change of lead of the active lead compound to lead sulfate giving a greater capacity at low temperature discharge.

2. For a storage battery of the lead-acid type, a plate having a paste thereon comprising an active lead compound and 0.1% to 2%, based on the 'weight'of the paste of an anion exchange amino dye insoluble in dilute sulfuric acid in small discrete particles as an expander.

CARL H. RASCH.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 723,328 Sperry Mar. 24, 1903 2,202,489 Hauel May 28, 1940 2,233,281 Brown et al Feb. 25, 1941 2,251,399 Cole Aug. 5, 194]. 2,514,415 Rasch July 11, 1950 OTHER REFERENCES Rowe, Colour Index, pages 348, 352-353, Society of Dyers and Colourists, January 1924.

Willihnganz, Nat. Lead 00., Research Labs, Lab. Publ., No. 63, 1942, pp. 1 and 2. 

1. FOR A STORAGE BATTERY OF THE LEAD-ACID TYPE, A PLATE HAVING A PASTE THEREON COMPRISING AN ACTIVE LEAD COMPOUND AND 0.1% TO 2%, BASED ON THE WEIGHT OF THE PASTE, OF AN AMINO ANION EXCHANGE BODY IN SMALL DISCRETE PARTICLES INSOLUBLE IN DILUTE SULFURIC ACID AS AN EXPANDER, SAID BODY COMPRISING AN AMINO ORGANIC DYE CONTAINING AN AMINO GROUP AND INSOLUBLE IN DILUTE SULFURIC ACID WHEREBY SAID COMPOUND ON DISCHARGE OF THE BATTERY FACILITATES THE CHANGE OF LEAD OF THE ACTIVE LEAD COMPOUND TO LEAD SULFATE GIVING A GREATER CAPACITY AT LOW TEMPERATURE DISCHARGES. 